1. Field of the Invention
The present invention relates generally to an ice making machine, and more particularly, to an ice making machine enabled to reduce ice making time and minimize the amount of water being wasted.
2. Description of the Background Art
An ice making machine is an apparatus for making pieces of ice by freezing water supplied from an external water supply. Recently, ice making machines have been proposed that enable the prevention of opacification of ice pieces, which occurs as air bubbles inside the water are frozen.
FIGS. 1 and 2 show a conventional ice making machine disclosed in U.S. Pat. No. 5,425,243. The conventional ice making machine, as shown in FIGS. 1 and 2, comprises a housing 10, a freezing unit 20, and an air removing means 30.
The housing 10 of the ice making machine comprises an ice bin 11 for storing pieces of ice produced by the freezing unit 20. A compressor 12 and a condenser 13 are disposed below the ice bin 11 within the housing 10.
The freezing unit 20 comprises a water tray 21, a freezing base plate 22, and an evaporator 23 as shown in FIG. 2. The water tray 21 is filled with water. A multiplicity of freezing fingers 24 are formed on the lower surface of the freezing base plate 22 for being dipped into the water to be frozen. A pivoting means 25 is disposed at one side of the water tray 21 for tilting the water tray 21 and discharging the water, which has not frozen and does not form ice pieces. The evaporator 23 is disposed on the upper surface of the freezing base plate 22 and is connected with a freezing system 12,13. Refrigerant flows inside the evaporator 23 to cool the freezing base plate 22 and the freezing fingers 24 by the heat exchange of the refrigerant.
The air removing means 30 for preventing opacification from occurring during the ice making process by removing air bubbles in the water to be frozen comprises a rocking plate 31 that rocks up and down inside the water tray 21, is and a rocking motor 32 for rocking the rocking plate 31. When an engagement piece 33 disposed in the rocking motor 32 hits an engagement pin 34, the rocking plate 31 rocks, thereby floating the air bubbles upwardly and outside the water.
The freezing unit 20 further includes a water supply pipe 14, a pivotal shaft 26, a water chute 27, and a water collecting section 15.
Hereinafter, the operation of a conventional ice making machine having the above structure is described.
When the water is supplied to the water tray 21 through the water supply pipe 14 and the freezing fingers 24 are dipped into the water, the water starts to form ice around the freezing fingers 24 cooled below the freezing point by heat exchange of the refrigerant flowing inside the evaporator 23. At the same time, the rocking plate 31 disposed under the water rocks up and down as the rocking motor 32 is driven. Accordingly, the air bubbles inside the water are removed and clear ice pieces are gradually formed around the freezing fingers 24.
After ice pieces having a predetermined size are formed around the freezing fingers 24, the rocking plate 31 stops rocking, and hot gas is discharged from the compressor 12 directly into the evaporator 23 without passing through the condenser 13, thereby warming the freezing fingers 24.
The water tray 21 is tilted on the pivotal shaft 26 by the pivoting means 25. Therefore, the ice pieces are separated from the freezing fingers 24, and drop into the ice bin 11, and the water remaining in the water tray 21 is discharged into the water collecting section 15 by flowing through the water chute 27.
Such conventional ice making machines require an amount of water exceeding what is actually to be frozen, as the water tray is designed to hold more than the amount of water necessary to make ice pieces, thereby wasting a lot of water that is guided into the water collecting section 15.
Moreover, since the freezing fingers 24 cool not only the water to be frozen but also the whole water in the water tray 21, excessive energy is consumed unnecessarily prolonging the time required to freeze the water around the freezing fingers 24.
An object of the invention is to solve at least the above problems and/or disadvantages and to provide at least the advantages described hereinafter.
Accordingly, an object of the present invention is to solve the foregoing problems by providing an ice making machine capable of minimizing the waste of water by supplying a predetermined amount of water into a multiplicity of freezing cells formed having a predetermined size and of shortening the time required to form ice pieces by increasing the freezing rate at which the ice freezes around the freezing fingers.
In order to achieve the above objectives, the ice making machine according to present invention comprises a housing, an evaporator connected to a freezing system, a base frame having a lower surface and a multiplicity of freezing cells for containing water to be frozen, a freezing base plate provided adjacent the evaporator and having freezing fingers formed on the lower surface of the freezing base plate to be dipped into the water retained by the freezing cells, and an ultrasonic transducer for removing air bubbles inside the water by vibrating the water contained in the freezing cells with ultrasonic waves.
The ultrasonic transducer preferably is disposed on the lower surface of the base frame.